Electromagnetic induction around us: surprising and familiar

2024 Author: Seth Attwood | [email protected]. Last modified: 2023-12-16 15:55

Electromagnetic induction is a very interesting phenomenon. It can be used to launch drones or recharge gadgets. What entertaining technologies of our time are associated with electromagnetic induction?

How long can you fly? “Until there is enough fuel,” says an airplane enthusiast. “Until the battery runs out,” says the owner of a fashionable drone. "As much as you like," says Samer Aldhaher of Imperial College London. Demonstrating the possibilities of wireless power transmission technologies, the physicist came up with a simple modification of a miniature quadcopter bought in a store and removed the onboard batteries from it. Instead, a simple spiral of copper tape is installed on the drone - being close to the inducing copper coil, the device remains in the air as long as you like.

The design of the Aldracher system is quite simple, but even simpler - a device for demonstrating electromagnetic induction in the wireless transmission of electricity, the assembly of which is shown in the YouTube video of the Ludic Science channel. To surprise others, to interest the child: all that is needed is a coil of copper wire, a transistor, a battery with which we will transmit energy, and an LED that we will try to light. All the details are explained in the video, and do not be alarmed that it is in English, the diagram is really nowhere simpler.

It is a pity that such simple systems are very ineffective: the induction coil distributes energy non-directionally, and the lion's share of it is lost without ever reaching the device being charged. However, radiophysicists find rather ingenious ways to circumvent this limitation. For example, Ossia is promoting wireless "chargers" built into walls or as free-standing devices - and capable of efficiently charging even such a voracious gadget as the iPhone. A special module on the smartphone itself sends out weak signals, some of which (both directly and reflected from the surrounding objects) fall on the charging device and allow you to determine the position of the smartphone in space. The rest is a matter of technology: response high-energy pulses are sent in the same directions in the opposite direction, with a frequency of 100 Hz.

Well, to get to the very bottom and find out how such devices work, there is nothing better than watching a good old movie. 20-minute popular science film "Electromagnetic induction". Published in 1978 at Lennauchfilm, it is not at all outdated, just as the laws of physics do not get old.